“No one knows how widely such lethal radio-active particles might be diffused, but the best authorities are unanimous in saying that a war with H-bombs might possibly put an end to the human race.”
Reasons and Persons paraphrased:
“I believe that if we destroy mankind, as we now can, this outcome will be much worse than most people think. Compare three outcomes:
1 Peace.
2 A nuclear war that kills 99 per cent of the world’s existing population.
3 A nuclear war that kills 100 per cent.
99% kill would be worse than peace, and 100% kill would be worse than 99% kill. Which is the greater of these two differences? Most people believe that the greater difference is between peace and 99% kill. I believe that the difference between 99% kill and 100% kill is very much greater. The Earth will remain habitable for at least another billion years. Civilisation began only a few thousand years ago. If we do not destroy mankind, these few thousand years may be only a tiny fraction of the whole of civilised human history. The difference between 99% kill and 100% kill may thus be the difference between this tiny fraction and all of the rest of this history. If we compare this possible history to a day, what has occurred so far is only a fraction of a second.”
So I think many people were worried about the extinction risk of nuclear war.
Russell-Einstein Manifesto (1955) link
“No one knows how widely such lethal radio-active particles might be diffused, but the best authorities are unanimous in saying that a war with H-bombs might possibly put an end to the human race.”
Reasons and Persons paraphrased:
“I believe that if we destroy mankind, as we now can, this outcome will be much worse than most people think. Compare three outcomes:
1 Peace.
2 A nuclear war that kills 99 per cent of the world’s existing population.
3 A nuclear war that kills 100 per cent.
99% kill would be worse than peace, and 100% kill would be worse than 99% kill. Which is the greater of these two differences? Most people believe that the greater difference is between peace and 99% kill. I believe that the difference between 99% kill and 100% kill is very much greater. The Earth will remain habitable for at least another billion years. Civilisation began only a few thousand years ago. If we do not destroy mankind, these few thousand years may be only a tiny fraction of the whole of civilised human history. The difference between 99% kill and 100% kill may thus be the difference between this tiny fraction and all of the rest of this history. If we compare this possible history to a day, what has occurred so far is only a fraction of a second.”
So I think many people were worried about the extinction risk of nuclear war.